A Deloitte auditor who was banned in 2005 from practising as an accountant for improper professional conduct has been reinstated by the Securities and Exchange Commission (SEC).

William Caswell was suspended for to his part in auditing Adelphia Communications’ accounts for the year ended December 31, 2000. At that time, Caswell was a director and held the most senior position on the Adelphia account.

The SEC found that Adelphia had understated its co-borrowing debt by $1.6bn and said Caswell should have been aware the accounts had not been prepared in accordance with US GAAP regulations.

His suspension was part of a settlement reached in 2005 between the regulator and Caswell. Under the terms of the original deal, he became eligible to apply for reinstatement after two years.

The SEC said he had complied with all the terms of the order, and could now practise again, subject to his work being reviewed by the independent audit commission at any company he works for.