The BBC has uncovered secret tape recordings made by the late media tycoon Robert Maxwell.
Maxwell's fraud affected 30,000 pensioners
The 79 cassettes include discussions with employees the businessman suspected of disloyalty.
Maxwell drowned in 1991 in mysterious circumstances, shortly before it was revealed he had stolen £100m from the Mirror Group's pension fund.
The tapes were discovered during research for a BBC Two drama about Maxwell's life.
They include a conversation with his finance director Basil Brookes while Maxwell was on board his yacht, the Lady Ghislaine, just hours before his death on 4 November 1991.
On one cassette the publishing baron, who associates have said had grown increasingly paranoid before his death, can be heard telling Mr Brookes to be careful to whom he showed a document because "there are too many eyes walk[ing] around in that office".
Maxwell had ordered John Pole, his then-director of security, to wire the telephone extensions of underlings he feared were challenging him.
These included board members of his two public companies, Maxwell Communications Corporation and Mirror Group Newspapers, and trustees of the Mirror Group pension fund.
The tapes, which date from the summer to November of 1991, had been kept by Mr Pole in a suitcase for 15 years.
A wire-tap system had been discovered in the Mirror's Holborn building after Maxwell's death but the actual recordings had not been heard until now.
A total of 30,000 pensioners were affected by Maxwell's fraud.
Maxwell, starring David Suchet and Patricia Hodge, will be shown on BBC Two at 2100 BST on Friday 4 May.