SPRINGFIELD, Mo. -- U.S. Rep. Roy Blunt on Wednesday defended federal agents who took criticism for the deaths of two dogs who succumbed to heat in a car as their owner was arrested in one of the Midwest's largest counterfeiting schemes.

In a report capping an investigation requested by animal advocates, Blunt said the agents took reasonable steps to protect the English Bulldogs July 11 and that the owner, Edward Clyde Allen Sr., ultimately put the animals at risk by using them to protect his alleged criminal activity.

Blunt, R-Mo., reached his conclusion after reviewing reports from the U.S. Secret Service and Greene County Sheriff's Department into the incident, which occurred just outside Springfield city limits. Sheriff's deputies assisted with the arrests.

'Unintended deaths'

"The deaths of the two animals is regrettable but was unintended," Blunt said.

Blunt also said it was unfortunate that the incident had overshadowed the arrest of two suspects in what is believed to be one of the largest counterfeiting operations in the Midwest in recent years.

Allen and his son, Edward Clyde Allen Jr., were arrested at a mobile home park after officers found $440,000 in phony money, as well as equipment to make money inside the elder Allen's home. The pair are also accused of passing about $320,000 in fake bills before they were arrested.

The $320,000 has turned up coast to coast, U.S. Attorney spokesman Chris Whitley said Wednesday.

"There's ample evidence that these two traveled around the country to pass the bills, and once (the bills) get into the system, they go everywhere," Whitley said.

Officers went to the home after a Springfield woman called the Secret Service to report that her sister's husband and father-in-law had been producing counterfeit money for about four years.

If convicted on all counts, Allen Sr. faces a maximum of 45 years in prison without parole and up to $1 million in fines. Allen Jr. faces up to 38 years in prison without parole and up to $750,000 in fines.

Humane Society criticism

Blunt initiated the inquiry after Allen Sr.'s public defender Evelyn Mangan, along with a Springfield veterinarian and the executive director of Southwest Missouri Humane Society, publicly criticized officers.

Mangan was critical Wednesday of Blunt's report, saying he never contacted her or her client about the incident.

"It appears that what he did is request an explanation from the Secret Service and the Greene County Sheriff's Department, and then accepted those explanations on face value," Mangan said.

Allen alleged the dogs -- Bonnie and Max -- were left unattended for about four hours in a hot car while officers arrested Allen and his son.

A Springfield police officer called for the city's animal control officer to remove the dogs, but they refused because the mobile home park is outside city limits.