The Wayne County Prosecutor said Friday she has opened an investigation following a newspaper report that Mayor Kwame Kilpatrick and his top aide exchanged sexually explicit text messages.
The messages appear to contradict the pair's denials in court that they had romantic ties.
"The Wayne County prosecutor's office will conduct an independent investigation that will be fair, impartial and thorough," Prosecutor Kym Worthy said at a morning news conference. "We will not be rushed by anyone or anything."
Worthy didn't elaborate on the specifics of her investigation, but said she was unaware of the text messages until she read a report in the Detroit Free Press on Thursday.
Question of perjury
The text messages raise the question of whether the mayor and Chief of Staff Christine Beatty committed perjury during a whistle-blower trial last summer.
A conviction of lying under oath can bring up to 15 years' imprisonment.
Also on Friday, a union president called for Kilpatrick to resign.
John Riehl, president of American Federation of State, County and Municipal Employees Local 207, said the union wants the mayor to step down right away. It has 900 members and represents workers in the city's water and public lighting departments.
"He's compromised the public trust," Riehl said. "Nobody can believe a single thing he says from now on."
'Extremely private messages'
Kilpatrick and Beatty during last summer's trial denied any sexual or romantic ties in 2002 and 2003. But the Free Press said it examined 14,000 text messages on Beatty's city-issued pager from those years and found many examples of such ties.
Kilpatrick's lone public statement about the messages was issued late Wednesday, shortly after the Free Press story was posted on the Internet.
"These five- and six-year-old text messages reflect a very difficult period in my personal life," he said. "It is profoundly embarrassing to have these extremely private messages now displayed in such a public manner."
On Thursday, mayoral spokesman James Canning said in a statement that Kilpatrick and his family were returning from Florida on Thursday evening "and plan to continue their private time for the next several days."