Former Barclays Chief Executive Bob Diamond told CNBC that he intended to buy more shares of the British bank. Diamond was ousted in July last year after UK regulators fined the lender for rigging interest rates. However, the former chief said the bank had grown stronger since his departure. As a result, he said he would be purchasing shares in the lender's GBP 6 billion rights issue.

Diamond said, "I'm buying my rights, I'm bullish on Barclays ... Barclays has become a better and stronger institution." He also lauded the current leadership. "It's got good strong new leadership in (Chief Executive) Antony Jenkins and (Chairman) Sir David Walker," he added.

According to Reuters, Diamond held 13.2 million Barclays shares in 2011. Reuters estimated that if Diamond were to take up all his rights in Barclays, Diamond would have to spend GBP 6.1 million.

Barclays would be undertaking the rights offering to raise capital and comply with stricter rules. The rights issue would allow shareholders to buy one new share at a price of 185 pence for every four shares they owned.