"It was a match from the European club competitions," Ristoskov told local tv Kanal 3 on Saturday. "I was offered $100,000 (to influence the outcome of the game) but I rejected it immediately."
Ristoskov declined to give any more details but added that his assistants in the game, Veselin Mishev and Yordan Ivanov, "know what it's about".
Mishev said there was only one European game in which he was a linesman with Ristoskov in charge.
"It was the UEFA Cup preliminary round match between (Azerbaijan's) Neftchi Baku and (Austria's SV) Ried but I don't know anything about 100,000 dollars," Mishev told Kanal 3.
The return leg of the tie was played on August 2 2007 in Baku with Neftchi winning 2-1 but losing 4-3 on aggregate.
"Neftchi needed a win by two 'clear' goals (to go through) as they had lost the first match 3-1. And they took a 2-0 lead but then Ristoskov sent off their captain and the Austrians scored one goal.
"I can tell you that Ristoskov did very well and we were rated very high," Mishev added.
Last April, Ristoskov was handed a four-match ban by the Bulgarian Football Union (BFU) for committing significant errors in the league match between CSKA Sofia and city rivals Slavia.
One month later, Ristoskov, who was beaten up by three masked men outside his home a couple of weeks after refereeing the 'eternal' derby between Levski Sofia and CSKA in 2006, decided to go to Austria and officiate in the lower divisions.
