A former aide to Chief Executive Leung Chun-ying has admitted "overlooking" restrictions on the activities top government officials may pursue once they step down. He started a company without consent just three months after leaving the government. Charles Kwan Wing-kei was appointed as a full-time member of top government think tank the Central Policy Unit last September, but ended his short stint as an adviser in April. According to the rules, Kwan is obliged to seek government approval before taking up any employment within a year of leaving public service. However, Companies Registry data show that a private firm named Minerva Consultant - owned by Kwan and another person - was established on June 28. A lawmaker said Kwan's oversight exemplified a lack of professional ethics on the part of Leung administration appointees. Kwan yesterday conceded that he had not obtained government approval to set up the company, but insisted its business - consultancy services related to publishing, translating and printing - did not represent a conflict of interest with his work at the central policy unit. "I have overlooked the restrictions," he said. "The company has been started but is not in operation yet. I thought I could set up the company first before filing an application to the government." Kwan said he was "reminded by friends" of the oversight and had this month sought government approval. "If it is not approved, I may have to sell the shares or dissolve the company," he said. Kwan initially held a 9.9 per cent stake in the firm. Last month, the government approved an application by Kwan to take up work at the Hong Kong Polytechnic University as a part-time research fellow. Civic Party leader Alan Leong Kah-kit said Kwan's excuse that it was an oversight on his part was "unacceptable". Leong said: "It is fair to conclude that had he not been caught out, he would simply have got away with it." "It just serves as another example of top officials in the current term not having the correct mentality when they take up public office. "They should have observed the rules more stringently," Leong said.