Liberia could prosecute a national who flew to the United States and was diagnosed with the Ebola for making a false statement on travel documents, the head of the West African nation’s airport authority said on Thursday.

Binyah Kesselly said the Liberian patient, Thomas Eric Duncan, was asked in a questionnaire as he left Monrovia airport if he had come in contact with any Ebola victim or was showing symptoms of the disease and he had replied ‘no’.

“I raised the question with the justice minister if we can prosecute people for knowingly making false declaration on forms where you willingly, knowingly and mortally put people’s lives at risk … She is of the opinion that we can,” said Kesselly.

“We hope he has a speedy recovery. We wait his arrival in Liberia: we will be open to prosecution. Knowingly making a false declaration is not a joke,” Kesselly said.

The Liberian government said Duncan failed to declare that he helped neighbor Marthalene Williams after she fell critically ill on Sept. 15. Duncan tried to arrange for a car to take her to a hospital, but failed.

“He took her on a wheelbarrow and sought help from a friend and called his office for assistance to take her to a health facility,” Information Minister Lewis Brown told the news conference. “But we know that she passed away in the wheelbarrow while en route to the health center.”

Duncan fell sick a few days after arriving in the United States and sought treatment at Texas Health Presbyterian Hospital last week but was sent home even though he told a nurse he had recently arrived from West Africa.

By Sunday, he needed an ambulance to return to the same hospital, where he was admitted and tested positive for Ebola.

Liberian President Ellen Johnson Sirleaf told Canadian Broadcasting Corp. on Thursday that she was angry with Duncan for what he had done, especially given how much the United States was doing to help tackle the crisis.

“The fact that he knew (he might be a carrier) and he left the country is unpardonable, quite frankly.”

Sirleaf said she wanted Duncan to be sent back to Liberia once he had been treated “and then we will have to deal with him”. She did not give details.

He was the second Liberian to carry Ebola to another country by air travel after Patrick Sawyer took the virus to Nigeria in July. Eight people died from that outbreak in Africa’s most populous nation.

However, Kesselly said that while Sawyer was already showing signs of Ebola when he left Liberia — and knew therefore that he was placing other travelers at risk — Duncan had no symptoms when he boarded his flight.