DETROIT -

There is a new, surprising development in the investigation into the 2010 death of a Grosse Pointe Farms woman.

According to documents filed in federal court, attorneys representing the family of JoAnn Matouk Ramain revealed a new witness has come forward. The witness, Paul Hawk, has sworn under oath that he saw Timothy Matouk with JoAnn near the water the night she went missing.

JoAnn Matouk Romain was last seen Jan. 12, 2010, at a prayer service at St. Paul on the Lake Catholic Church. Her car, with her purse, wallet and cash inside were found in the church parking lot.

Investigators said they tracked footprints in the snow from the lot to Lake St. Clair and searched the waters, but no traces of Romain were found. Then, in March of that year, her body was found by fishermen in a channel of the Detroit River near Amherstburg, Ontario.

Timothy Matouk is JoAnn's cousin. He holds a high-profile job as an investigator with the Wayne County Prosecutor's Office. An attorney representing JoAnn's family said he believes the information this new witness has shared could take the case in a new direction.

"Do the right thing, and that is: question their own. Now, we know that Tim Matouk knows a lot more than he is saying, and that's all that we want him to do," said attorney Ari Kresch.

The witness said he went to police years ago with a description of Timothy Matouk but claimed investigators became aggressive and hostile, accusing him of giving false information to police.

Attorney Solomon Radner said he believes he knows why.

"Well, we think it was part of the cover-up. He was giving them information that they didn't want, that they didn't want to hear, that they didn't want to investigate because it immediately casted a shadow on the conclusions that they wanted to make," said Solomon.

Police said Romain's death was a suicide. Her family claims it was a murder and have taken legal action.

Read back: Family sues police over mother's unsolved death

The lawsuit now includes this new witness statement.

"There is no way you could imagine that a law enforcement officer who had someone point a finger at him wasn't checked out by the state police, by the FBI, by the local police. So, for this affidavit to have any credence and any credibility the officers would have to be lying," said attorney and legal expert Todd Flood.