The family of a murdered gay politician in the US state of Mississippi are renewing their push for a federal investigation and will hold a news conference on Thursday.

Marco McMillian, 33, was found dead on 27 February near the Mississippi River west of Clarksdale, the city where he was running for mayor.

The case drew national attention after his campaign said he was the first viable, openly gay candidate for office in Mississippi.

In March, the FBI said it would “assess evidence to determine whether federal prosecution is appropriate.”

McMillian’s sexuality wasn’t a campaign issue, but because he was gay and black, some speculated his death might have been a hate crime. The suspect, who is in custody, also is black.

Mississippi’s hate crimes law covers acts motivated by bias against a victim’s race but not sexual orientation.

However, a federal hate crimes law covers bias against sexual orientation and local and state agencies can seek assistance to pursue a federal hate crime under the Shepard-Byrd Hate Crimes Prevention Act.

The Act was introduced in 2009 as is named after murdered gay teenager Matthew Shepard.