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."
Gilbert has released a new line of rugby cleats. The Gilbert Virtuo 8S is part of the exciting new product. Check it out.
The entire All Blacks apparel line has been updated for 2013/14. Check out the New Zealand All Blacks polo.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
The Gilbert Blitz 8S rugby cleat is a great cleat at a great price of $69.99. Get a new pair of cleats today.
A cool looking all black rugby cleat with the high performance adidas is known for. Get in the Gear!
Wear the crest of the British and Irish Lions on your t-shirt. A great look for the summer.
$29.99
The All Blacks Performance t-shirt is black with hints of blue from the training jersey. Very Cool.
The New Zealand All Blacks training jersey for 2013/14. Get in the Gear!
The USA Rugby Pro Alternate rugby jersey is perfect for any fan of the Eagles. Get yours to wear during the summer Test matches.
The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.