The female driver arrested for trespassing into the compound of the Ministry of Foreign Affairs (MFA) on Monday has a history of mental illness, said the police and Immigration & Checkpoints Authority (ICA).
The 27-year-old woman, a Malaysian, has since been arrested for criminal trespass and is being investigated for evading immigration clearance, the two Home Team agencies said in a joint statement on Tuesday evening.
"With the assistance of the Malaysian High Commission and the Royal Malaysia Police, we have since contacted her next-of-kin in Malaysia who are on their way down to Singapore to assist in our investigations," said the police and ICA.
The woman had entered Singapore in a Malaysian-registered car on Jan 17 via the Woodlands Checkpoint at about 1.58pm by tailgating another car, according to preliminary investigations.
She managed to leave the checkpoint minutes later without being stopped as officers-in-charge did not immediately raise the alarm. When the alarm was raised, efforts to locate the car in Woodlands checkpoint were unsuccessful despite a lock down of the arrival car zone, the statement read.
On Monday, she then tailgated a taxi for an hour. Later that day, she also managed to enter the front gate of The Ministry of Foreign Affairs without proper authorisation by tailgating another vehicle.
ICA and the police said that even though there was no immediate threat to public safety, the case is taken seriously as "it concerns the security of our borders". Both ICA and the police said they will review the incident and take necessary steps to prevent a recurrence. "In particular, we will review our security systems and work processes in place at the Checkpoints," the statement read.
In a separate statement on Tuesday evening, Deputy Prime Minister Teo Chee Hean said he has expressed his dissatisfaction to the Commissioner of ICA and the Commissioner of Police over the breach at Woodlands Checkpoint and the subsequent response actions.
Mr Teo, who is also Minister for Home Affairs and Coordinating Minister for National Security, added: "This case, which could have had more serious consequences than what occurred, should have been prevented and dealt with more urgently and decisively. I have directed the Commissioners to report to me the corrective actions they are taking, and recommend appropriate action to be taken against officers who have not discharged their duties properly."