Federal prosecutors are seeking to get $31,060 from a retired Plainfield, Conn., police officer who was convicted of participating in a drug deal that happened in a Nashua hotel room last February.

Richard Thunberg Jr., who is serving a two-and-a-half year sentence in a Massachusetts jail, handed over $31,060 in cash to undercover officers at a hotel room Feb. 17, buying what he believed was two pounds of crystal methamphetamine, according to prosecutors.

On Monday, federal prosecutors in New Hampshire filed a request with a judge to seize the cash along with a pair of guns used by co-conspirators in the case.

Prosecutors say that Thunberg Jr., 51, became the target of an investigation after they arrested a Quincy, Mass., man and his roommate in November 2010 on drug charges.

Investigators arrested one of the men just as he received a shipment of crystal methamphetamine shipped from California.

As part of the same investigation, undercover officers arranged a drug buy with Thunberg, prosecutors said.

“The undercover agent were to supply Thunberg with what he believed to be a two pound supply of ‘Ice’ methamphetamine in return for cash payment,” Assistant U.S. Attorney Robert Rabuck wrote.

Thunberg first met a “cooperating source” working with investigators on Feb. 17 at a Chili’s restaurant in Lowell, Mass., before heading to the Nashua hotel room, where police had him under surveillance, Rabuck wrote.

“Thunberg entered the hotel room with $31,060, which was wrapped in numerous assorted money bands,” Rabuck said in his petition.

Thunberg gave the money to the undercover officers and took “what he believed to be two pounds of crystal ‘ice’ methamphetamine,” prosecutors wrote. Thunberg was stopped by Massachusetts State Police after he crossed back into the Bay State. He was charged with intent to distribute controlled substances.

Thunberg pleaded guilty in April to one count of possession with intent to distribute methamphetamine in Middlesex (Mass.) Superior Court.

Prosecutors on Monday asked a federal judge to approve seizing the money, guns and other assets because Thunberg and his co-defendants failed to respond to the claim.

jkimble@newstote.com