Robert Abela, who headed Malta's contingent, said many results were "not based solely on the public vote".
He added "five or six" other countries during Saturday's contest were angered by block voting - where neighbours back each other regardless of the song.
Serbia's Marija Serifovic won the contest, watched by 10.9m in the UK.
The show, which was broadcast on BBC One on Saturday night, drew 50.8% of the viewing share.
Mr Abela said he had received some reports indicating how many points Malta would get from certain countries even before the semi-finals, which saw Malta knocked out of the contest.
"If the EBU (European Broadcasting Union) cannot 100% monitor how the system is being done in some of the ex-Soviet countries, I think they should do away with (phone voting)," he said.
"I know it is not 100% tele-voting, and I personally believe these countries are messing with them."
He said he would be willing to approach the EBU, along with several other countries, to take action over the "block voting".
He also confirmed that the 12 points Malta awarded UK entry Scooch - over half their final total - was a protest at the way so many countries vote for their neighbours.
Criticism has also surfaced in Germany where local tabloid newspaper Bild questioned why Western European countries should pay the largest amount for a competition they seem to have no chance of winning.
Olivia Lewis performed Vertigo for Malta at the contest
It quoted singer Nicole, Germany's sole Eurovision winner, as saying: "It is obvious that Eastern European countries engage in dirty trade with points every year.
"Germany should withdraw from the competition."
The EBU were unavailable for comment.
BBC DJ Paul Gambaccini told Radio 4's Today programme he thought about half of the voting was for political reasons.
He said: "Britain's votes plummeted with the invasion of Iraq and have stayed in the basement with the occupation.
"It may be the strangest reason for ending a war but if you want to win the Eurovision Song Contest again, bring the boys home."
He added: "There has always been a political dimension to Eurovision, the love-fest between Greece and Cyprus has been noted for a long time.
"Now with the public voting instead of the panel voting it is really extensive."
'No borders'
Sir Terry Wogan, who commentates for BBC One on the contest each year, told the BBC News website on Saturday he was genuinely aggrieved at the political machinations of the competition's voting.
"It's a pity it's not about the songs any more," he said.
"There's a definite Baltic bloc and a Balkan bloc and they've been joined in recent years by a Russian bloc.
"I've said it so many times it has become a cliche. We won the Cold War but we lost the Eurovision."
Marija Serifovic said she did not think about these issues: "I don't know anything about politics, I'm just a singer.
"There are no borders for music. The only important thing in my life is music."
Even with Malta's protest vote the UK entry, Scooch, finished joint 22nd out of 24.
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