The probe into the run on Northern Rock last night widened to include hedge funds, private equity transactions and ratings agencies after the UK's powerful Treasury Select Committee asked for new evidence for its investigation and indicated that it could call back parties already interviewed, as well as the UK's Chancellor of the Exchequer, for fresh questioning.

The committee, which yesterday lambasted Northern Rock's board for failing to arrange sufficient credit facilities to insure against problems accessing public funding, has invited submissions of written evidence from "interested parties" which must be filed by November 7.