The fresh approaches have come after Wasps revealed they were in danger of going into administration after a takeover deal fell through.
It is understood Wasps have enough funding to see them through the next month, which would allow them to complete the Premiership season, but the club need urgent investment to remain in business beyond May.
Wasps have returned with their begging bowl to three parties who had previously expressed an interest in the club while issuing an appeal for potential new investors to step forward.
Wasps lose £2million a year and a new owner would have to repay a secured loan of £1.5m.
However Rigby is confident that the renewed interest in Wasps will help secure the club's survival.
"We have had quite a variety of approaches, from traditional investors to people who manage money on behalf of wealthy individuals," Rigby told The Daily Telegraph.
"I do believe, with the interest that was already there and the new interest that has emerged, it will come together and produce a successful sale."
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