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 had been looking for traces of Allan at the River Leven search near the old Tullis Russell plant, but that no evidence had been found.
A Police Scotland spokesman said: “We have concluded the searches at the river in Glenrothes and nothing of note to the investigation was found. Allan’s family have been updated.”
Earlier police said that they were “acting on information received from the public” in undertaking the search.
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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