Portland police and FBI investigators have more than doubled a reward for information about a missing man from Boston who was last seen in Portland nearly 20 years ago.

Authorities announced Thursday that the reward has increased from $10,000 to $25,000 for any information that leads them to Miguel Oliveras or his remains.

The man from Boston’s Hyde Park neighborhood was last seen around 1 a.m. on Sept. 2, 2006, at the Platinum Plus Club on Riverside Street. Authorities say his disappearance is suspicious and they haven’t received any reports of sightings since then.

Oliveras would now be 44 years old, according to the National Missing and Unidentified Persons System.

Police described Oliveras as a Hispanic man with black hair and brown eyes. When he went missing, he was 5 feet, 11 inches tall; weighed about 170 pounds; and had tattoos on his neck, back, shoulder and hand.

Oliveras’ mother, Myrna Gonzalez, said in a written statement that his disappearance has been agonizing and urged people to come forward with information so she can have closure.

“Someone out there knows something, and even the smallest detail could make a difference,” FBI Special Agent Ted Docks said in a statement. “Miguel’s mom Myrna deserves answers, and she deserves the chance to lay her son to rest, to grieve, and to begin to heal. We’re urging anyone with information on Miguel’s whereabouts to contact us.”

Investigators are asking anyone with information about Oliveras to call Portland police at 207-874-8575, or to text “PPDME” and a message to 847411. They can also contact the FBI at 800-225-5324 or submit a tip online at tips.fbi.gov.