Allan, who went missing aged 23 in 2013, was last seen after leaving the town’s Styx nightclub in the early hours of November 3.
No trace of him has ever been found, despite one of the longest police searches in living memory.
Police confirmed today that specialist divers are looking for traces of Allan.
A Police Scotland spokesman said: “Acting on information received from the public, specialist officers from Police Scotland’s Marine Unit are today conducting a search of the River Leven in Glenrothes as part of the ongoing investigation into missing man Allan Bryant.
“Anyone with information about Allan’s whereabouts, or his movements after leaving Styx nightclub in the early hours of 3rd November 2013, is urged to contact Police Scotland on 101 quoting Operation Toner.”
In 2015, some skeletal remains were discovered in Riverside Park, however forensic evidence ruled out Allan.
In 2017, a home in the town’s Barton Place was sealed off for almost a month while police conducted an extensive search of the property and garden.
Earlier this year Allan’s father, Allan Snr sent a petition in to the Scottish Justice Secretary calling for him to appoint a new police team to take over the investigation into his son’s disappearance.
More than 5600 have signed the petition, which Allan Bryant Snr described as an “amazing response”.
A BBC crimewatch appeal was recently aired in the hope of generating new leads.
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