Sen. Norm Coleman, responding to a call Tuesday for investigations into allegations that a friend and political donor attempted to steer $75,000 to him, said he would welcome any investigation.

Coleman said he is “being used as a tool of extortion by private parties.”

In a Texas civil lawsuit filed shortly before the election, the former CEO of Texas-based Deep Marine Holdings said that Minnesota businessman Nasser Kazeminy used the company to funnel money to an insurance company that employs Coleman’s wife. A second lawsuit, filed in Delaware by Deep Marine shareholders, makes similar allegations.

Coleman, Kazeminy and officials with the insurance broker, Hays Companies, have all denied the allegations.

Coleman’s statement came shortly after the Alliance for a Better Minnesota, a coalition of Democratic-leaning groups, held a news conference calling on the Senate Ethics Committee and the FBI to look into the allegations.

“It is an important matter to determine whether Senator Coleman had knowledge of the alleged scheme, received benefits from it, and properly disclosed and accounted for what might be a substantial gift,” Denise Cardinal, the group’s executive director, wrote in a letter to Ralph Boelter, special agent in charge of the FBI’s Minneapolis office.

The Senate Ethics Committee does not release information on whether it’s initiated a preliminary inquiry into allegations against a senator. An FBI spokesman in Minneapolis also wouldn’t comment on whether there’s any investigation into allegations raised in the lawsuits.

Coleman is headed toward a recount in the U.S. Senate race where he currently holds a 206-vote lead over Democrat Al Franken. In a statement from his campaign, Coleman suggested he’s an innocent bystander.

“The fact that a United States Senator is being used as a tool of extortion by private parties should be of concern to all Minnesotans,” Coleman said.