Sabah Umno chief Bung Moktar Radin today claimed that vote-buying occurred in yesterday's Sandakan by-election.
"Some voters are telling me there was money used. We are checking on the allegations," he was quoted as saying by The Star.
Last night, DAP's Vivian Wong retained the Sandakan parliamentary seat with an 11,521 vote majority, against PBS' Linda Tsen and three independent candidates.
Tsen, who was backed by BN, only managed to secure 4,491 votes.
Bung had previously claimed that Umno would mobilise 9,700 members in the constituency to vote for PBS.
However, The Star quoted him as saying that the party only managed to mobilise 3,500.
The Kinabatangan MP cited a lack of funds as the reason why outstation voters could not be brought back.