A state senator who lost the Democratic primary last month was arrested by the FBI on Tuesday and charged with accepting $23,500 in bribes from undercover agents she believed were local businessmen.

Sen. Dianne Wilkerson was charged with attempted extortion as a public official and theft of honest services as a state senator. She did not enter a plea during an initial court appearance Tuesday.

She faces up to 20 years in prison and $250,000 in fines on each count.

Wilkerson, 53, lost the Democratic primary in September to former teacher Sonia Chang-Diaz despite support from Mayor Thomas Menino and Gov. Deval Patrick. She is running a write-in campaign for the Nov. 4 election, in hopes of retaining the seat she has held since 1993.

Wilkerson was ordered Tuesday to have no contact with witnesses and retain any documents related to the extortion case or to her personal finances.

In asking for those conditions, Assistant U.S. Attorney John McNeil said Wilkerson has a "long history of acting as if she is above the law."

Wilkerson's attorney, Max Stern, said she would obey the judge. She has been released on an unsecured $50,000 bond.