Former BBC CTO John Linwood, who was fired from his role in July last year, has hit back at the organisation, issuing legal proceedings and saying some of the failed £125 million Digital Media Initiative is in use.

The BBC only confirmed at the end of last week that Linwood, who was suspended over the DMI debacle in May, had been removed from his role but that news of his dismissal had been delayed for legal reasons.

In Linwood's written evidence to the Public Accounts Committee, he said: "I have issued legal proceedings against the BBC and intimated contractual claims, and am still involved in an internal process with the BBC."

Although Linwood said that the project was difficult and experienced delays, he refuted the idea that the DMI had been a waste of money.

"We delivered a substantial amount of the DMI technology," he said. "The technology we delivered worked, or could, with limited further testing, have worked. It is either in use in the BBC today or capable of being used.

"The BBC has written off working software and hardware, some of which remains in use today.

"The BBC has allowed inaccurate statements to be made to the PAC to the effect that the 'kit doesn't work' and is 'worth nothing'."

In his evidence, Linwood said that the primary reasons for the delays was the significantly large number of changes requested by the business to the requirements which had been previously specified by them. He said that while some technology issues had caused delays, all major technology issues had been addressed by October 2012.

Linwood revealed that the Metadata Archive and Physical Stock and Loan pillars of the DMI "went live in June 2012 and remain in use by thousands of users in the BBC today".

He charged that during early 2012, "it had become evident that the business was not speaking with one voice in relation to its requirements for Production Tools [a pillar of the DMI] and that there was no senior owner on the business side who would take responsibility for implementation of the technology.

"I raised these concerns at the highest level in the BBC and the Executive with whom I spoke had some success in persuading BBC Vision to appoint a senior executive to the Steering Group. However, after the former Director-General and the Chief Operating Officer departed in late summer/early autumn 2012 a change in direction by the business became apparent for the first time."

Linwood used an analogy to describe the BBC's change of direction for the DMI project, saying "this change was equivalent to removing the first half of a production line in a factory and still expecting the factory to deliver the original products".

He also criticised the £53 million write-down of the project by the BBC Executive Board in May 2013.

"In light of what had been delivered, the technology which was in use and ready to be used, my view was and remains that the scale of the write-down was unjustified. The reason for the write-down was because the BBC did not wish to take live one pillar of the technology it had commissioned, and which we had delivered, due to its change of vision and direction."

The PAC also heard from Bill Garrett, the former head of technology for BBC Vision Productions.

Garrett said: "It is clear that this project failed because despite [sic] claims that the DMI team did not deliver a working solution. It is my belief that this was as a result of very poor technical direction at the BBC evident in the DMI team's inability to show me technical designs for the proposal.

"From the outset the technical leadership of DMI appeared mismatched with the skills required for such a project. This was compounded by a lack of understanding by the team of contractual boundaries by BBC had in place with many of its technology providers who would be necessary stakeholders.

"In essence the DMI team did not grasp the scale of the challenge."

Garrett concluded his written submission to the PCA: "The BBC does deliver large scale technology projects very well. Many of my former colleagues are committed to delivering value for money for the licence fee payer, however there remains a number of individuals within the leadership of the Technology and North divisions of the BBC who need to account for their actions in relation to the management of DMI."

Senior members of the BBC, including former director general Mark Thompson, will appear before the committee on February 3.