ZAPATA, Texas — The Mexican government tells The Associated Press it's opened a federal investigation into the reported shooting of an American tourist on a U.S.-Mexico border lake.
A statement from Mexico's Ministry of Foreign Affairs provided to AP also "categorically rejects claims to the effect that Mexican authorities are not doing enough to find" Dennis Hartley.
Tiffany Hartley says her husband was shot and killed by Mexican pirates on Falcon Lake Sept. 30 as they returned on Jet Skis from a sightseeing trip into Mexico.
Texas Gov. Rick Perry and the Hartley family have said Mexico is dragging its feet in investigating Hartley's disappearance and looking for his body.
A spokesman for the Tamaulipas, Mexico, state prosecutor's office says the search of Falcon Lake resumed early Friday.
THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below.
ZAPATA, Texas (AP) — Hundreds of people using speedboats, helicopters and all-terrain vehicles are searching for a missing American tourist presumably shot and killed by Mexican pirates on a border lake, authorities in Mexico say.
Word that the search had intensified came after U.S. officials said threats of an ambush from drug gangs temporarily thwarted efforts.
Tiffany Hartley said her husband, David, was shot to death by Mexican pirates chasing them on speedboats across Falcon Lake on Sept. 30 as they returned on Jet Skis from a trip to photograph a historic Mexican church. Neither his body nor the Jet Ski has been recovered. Texas officials have warned boaters and fisherman that pirates frequent the Mexican side of the lake, a 25-mile by 3-mile dammed section of the Rio Grande.
U.S. Rep. Henry Cuellar told reporters that Mexican authorities were doing everything they could while trying to keep their own crews safe.
"When darkness was falling (Wednesday evening), they got word that there might be an ambush," Cuellar said. "People that are trying to do their job on the Mexican side are facing a risk, they're right inside the hornets' nest ... they had to suspend the search."
Cuellar said the search resumed midmorning Thursday.
That part of Tamaulipas state is overrun by violence from a turf battle between the Gulf Cartel and the Zeta drug gang, made up of former Mexican special forces soldiers, and both are battling the Mexican military.
Texas Gov. Rick Perry, campaigning for re-election in Houston, said such threats were no excuse.
"I don't think we're doing enough. When you call off the search the way they did ... and give as the reason because the drug cartels are in control of that part of the state, something's not right," Perry said. "We do not need to let our border continue to deteriorate from the standpoint of having drug cartels telling whether or not we can go in and bring the body of an American citizen who was killed. That is irresponsible."
Jesus de la Garza, Tamaulipas state deputy attorney general, said late Thursday that Mexican authorities increased their efforts under orders from Tamaulipas Gov. Eugenio Hernandez, whose office was contacted by a member of Perry's staff. Divers also were deployed, de la Garza said.
The lake appeared calm Thursday afternoon. From the border markers in the water, the only sign of activity on the Mexican side was a single helicopter, which appeared to be a Mexican military aircraft, flying overhead.
Zapata County Sheriff Sigifredo Gonzalez said he has sent word to the Zetas that he wants the body returned and has no plans to prosecute.
"We cannot arrest anybody for what happened in Mexico, we cannot prosecute on the state level anybody for what happened in Mexico. We just want a body," Gonzalez said. "I did send word to the drug cartel, the Zeta cartel in Mexico, I sent word to them unofficially. I can't tell you how but I sent word to them."
Gonzalez said he has not received a response.
Cuellar, a Texas Democrat joined by two other area congressmen, said Mexico was "doing the best that they can."
Martin Cuellar, sheriff of nearby Webb County and the congressman's brother, said Mexico started searching for Hartley on Friday, the day after the call about the shooting came in.
Ruben Rios, a spokesman for the Tamaulipas state prosecutor's office, said Tamaulipas authorities have not opened an investigation into Hartley's death because they don't have a formal complaint.
"There isn't a complaint, there isn't a body, we don't have anything to go on and open an investigation," he said.
Henry Cuellar released briefing papers shortly before a joint U.S.-Mexico news conference that said U.S. consular officers had accompanied Tiffany Hartley to the Mexican consulate in McAllen, Texas, to file a Mexican federal complaint. But no complaint with state authorities had been filed that would trigger a local murder investigation.
Drug war violence has spread in the last few months from Ciudad Juarez, the epicenter of Mexico's drug war across from El Paso, Texas, to the Gulf Coast region of Mexico, including Tamaulipas state where Hartley reportedly disappeared. Two drug gangs, the Gulf Cartel and the Zetas, are battling for supremacy there and fighting the Mexican military.
Associated Press writers Olga Rodriguez in Mexico City, Juan A. Lozano in Houston and Jeff Carlton in Dallas contributed to this report.