His father and elder sister held a press conference to apologise.

The visit last month came to light after one of the guests shown round posted photographs of the trip on her social media account.

One of the photographs shows her sitting at the controls of an Apache helicopter, with the instrument panel clearly visible.

Another pictures her husband wearing a pilot’s helmet inside the cockpit.

Lao’s father, a retired high-ranking army official, said he wanted to apologise to the Taiwanese public and the military because his son’s behaviour had created unease about security and damaged the armed forces reputation.

The military has punished at least 20 high-ranking officials over the incident, including the chief of the general staff.

Defence Minister Kao Kuang-chi has also apologised to the public and offered his resignation. President Ma Ying-jeou refused to accept it and has asked him to stay on.

Lao had originally told military investigators that he took a group of 20 people to tour the base, but prosecutors found there were 26 people and that 15 went into the facility housing the attack helicopters.

The Japanese visitor Naoto Hirayama was summoned for questioning by prosecutors and released, but has been barred from leaving Taiwan until the investigation is completed.

Investigators also found that Lao wore a helicopter pilot’s helmet and full flight suit to a Halloween party last October and that he invited another group of family and friends for another tour on February 22.

A task force, formed under Kao’s order, also discovered that another officer had compromised security at the base.

A brigade commander who invited four of his friends and relatives to visit in February has been removed from his post.