Leighton denies culture of corruption and cover-ups Former Leighton Holdings' chief executive Wal King has denied claims he was aware of bribery and fraud allegations made against the building giant. Mr King's comments came as Leighton Holdings said it was "deeply concerned" about bribery and fraud allegations made against the firm, but denied it had a culture of corruption and cover-ups. Denials: Former Leighton Holdings CEO Wal King. A Fairfax Media investigation published today said hundreds of confidential company documents revealed that top executives, including the highly respected Mr King, knew about the corruption claims.The allegations include the payments of kickbacks in Iraq, Indonesia, Malaysia and other countries, as well as other serious corporate misconduct. Mr King said today he had no prior knowledge of any wrongdoing at the company and that he had not been contacted by the police, Bloomberg reported. Shares in Leighton Holdings fell by up to 10.5 per cent today after opening at $19.58 following the claims. It was trading at $17.77 about 1pm. Leighton said in a lengthy ASX statement this morning it had voluntarily reported to the Australian Federal Police in 2011 a possible breach of its code of ethics after accusations of bribery payments in Iraq. The construction firm stressed that it was continuing to work with the AFP over the investigation, and was "not aware of any new allegations or instances of breach of our ethics." Leighton added that fraud allegations in relation to a barge construction in Indonesia were internally investigated and resulted in the company taking a former employee to the NSW Supreme Court to recover $5.6 million. Leighton added that the case was still before the court. Leighton said its board acted in the best interests of its companies and its board members were "aware of their responsibilities and have at all times executed their duties with the appropriate care and diligence." The contractor said that since it discovered a possible breach to its code of ethics in 2011, it initiated an internal review which led to the sacking of a senior executive the following year, an overhaul of its management structure and improved corporate governance and risk management processes. Leighton revival in recent years Leighton recently enjoyed a share price resurgence, following a raft of new projects worth up to $6 billion in recent months. The construction firm is also expected to benefit from Prime Minister Tony Abbott's pledge to build up Australia's infrastructure. Shares rose as high as $24.29 in February, after the company recorded a full-year profit of $450 million following a net loss of $285.5 million in the previous reporting year. Earlier this year, Leighton's board was rocked by turmoil when then chairman Stephen Johns, along with two other independent directors, resigned following differences with major shareholder Hochtief. The firm was also hit by profit downgrades after cost blowouts on Brisbane's Airport Link and the Victorian desalination plant. "It's not something that Leighton would welcome," Morningstar analyst Ross MacMillan said about the allegations, citing the company's recent profit growth under chief executive Hamish Tyrwhitt. We are certainly reassured by the processes that Hamish Tyrwhitt has introduced, and also the fact that a number of these allegations have been investigated by the company. ... But we'd like to see Leighton address any issues that were raised in the newspaper articles as soon as possible and potentially clear up any allegations that are there. The Fairfax Media investigation also revealed that the corporate watchdog, the Australian Securities and Investments Commission, appeared to have failed to conduct rigorous investigations into the allegations Leighton alerted the AFP about in 2011. Shares in Germany's largest construction company, Hochtief, which owns 56 per cent of Leighton, fell 7.9 per cent in trading following the report. Hochtief experienced its biggest fall in almost two years, dropping 5.15 euro to 60.20 euro in Frankfurt trading. Shares in Hochtief, which is controlled by Spain's Actividades de Construccion & Servicios SA, have soared 37 per cent this year. Hochtief's spokesman Christian Gerhardus declined to comment, Bloomberg reported. BusinessDay, with Nick McKenzie, Richard Baker and Bloomberg