For at least two years, according to the linked article.

For this UK-dweller, it's all very reminiscent of Jonathan Aitken, who swore "to cut out the cancer of bent and twisted journalism in our country with the simple sword of truth and the trusty shield of British fair play", and whose story got twistier and twistier until it collapsed with a final damning piece of evidence, after which he served seven months in jail for perjury.