A sports anti-corruption consultant says professional gamblers are avoiding betting on World Cup matches involving host nation Russia because of doubts over their integrity.
"I'm certainly worried about it," Mark Phillips, director at Global Sport Integrity, said.
"I know there are professional gamblers who are looking at these matches in Group A — Russia, Uruguay, Egypt and Saudi Arabia — and saying we can't bet on those games, because they don't know if they're going to be completely straight."
Mr Phillips admits the evidence for integrity breaches is purely circumstantial, but he argues the reputation of soccer's governing body FIFA has been badly damaged.
Allegations of kickbacks and bribery within FIFA came to a head eight years ago, during the bidding process for the rights to hold the 2018 and 2022 World Cups, which were eventually awarded to Russia and Qatar respectively.
"I think Russia has been very lucky that Qatar won 2022," sports administrator and FIFA whistle-blower Bonita Mersiades said.
"That was such an absurd decision for this tiny little state in the middle of the desert to win a World Cup tournament, that everyone ignored the fact that Russia won in two rounds of voting.
"The fact is FIFA did not make those decisions as to who would be the host of the 2018 and 2022 World Cups based on the evidence, based on the merits of the case, in either case."
After a series of arrests of FIFA officials, and the banning of former FIFA president Sepp Blatter for six years, the sports organisation argues it has turned a corner.
But many remain deeply sceptical.
"What we see with the current regime of FIFA is identical to what it was before," said the head of the Skins sportswear company Jaimie Fuller, who has been campaigning to eliminate corruption in international sport.
"There has been no change. There's a lot of spin going on, they're trying to sell us this is a reformed FIFA — they're definitely not."
'There should be concerns'
World Cup host nation Russia has sports integrity problems of its own.
Russian athletes were banned from competing under the country's flag in this year's Winter Olympics because of systematic breaches of anti-doping rules.
Fuller says a former Russian anti-doping official has told him there's at least one player in the country's World Cup football squad who has had a positive doping test covered up.
"There should be concerns after the way that Russia behaved in previous competitions, not just football but through the Olympics as well," Fuller said.
Against this background, Phillips is concerned that Russia appears to have been given an easy ride in the group stages of the World Cup.
"By at least one metric, the Elo rankings, Russia managed to get the easiest draw of any modern World Cup," he said.
Phillips also points to the fact that FIFA knocked back all seven match officials recommended by the English Football Association to officiate in the 2018 World Cup matches.
This will be the first World Cup without British referees since 1938.
"The question is whether they were rejected by FIFA or were they rejected by Russia?" Phillips said.
"It looks like they were rejected by Russia, and if they were rejected by Russia, why is Russia having any say on who referees at the World Cup?"
Two match officials from the original FIFA approved list will no longer be attending — one from Kenya resigned after allegations of bribery and one from Saudi Arabia was banned following allegations of match fixing.
"The referees haven't been announced yet for the individual matches, but there should be the highest amount of scrutiny on the referees who are given these matches involving Russia," Phillips said.
"When you're looking at putting a risk profile on each of these games, the Russia matches all come out as high risk."