There is obvious doubt in the number of confirmed novel coronavirus infections in Taiwan that the island has reported to the mainland, according to information provided by the National Health Commission and local Taiwan affairs office.

The island's health department notified the mainland on Wednesday one passenger who had taken a charter flight to Taiwan from Wuhan, Hubei province on Monday was confirmed to be infected with the virus on Tuesday.

However, the Taiwan affairs office of Wuhan said on Friday the man in the case reported by the island told the office that he hasn't been infected.

Due to the lockdown of Hubei province to curb the spread of the novel coronavirus, many Taiwan residents who live in the province, there on a business trip or traveling can't return to the island because all flights have been canceled. 

To help them return home, the mainland arranged to put them on charter flights. The first batch of 247 Taiwan residents took a charter flight to Taiwan from Wuhan on Monday.

According to the Taiwan affairs office of Wuhan, the Taiwan residents who took the charter flight back to the island have all made written commitments on their health conditions and have had quarantine inspections as required.

The office said it has been keeping in touch with the Taiwan residents who took the flight from Wuhan to the island to track their health condition.

The office contacted the Taiwan resident in the confirmed case reported by the island and found the man hasn't been infected with the virus, it said.

From Wednesday afternoon to Friday morning, the office contacted the man several times and was told he was fine, his CT scan result was normal and he has never received any notification of confirmation.

The "confirmed case" on the charter flight raised concerns in the island.

In recent days, island authorities have been speculating about the "confirmed case", and made use of it to delay more charter flights to take Taiwan residents back to the island, the office said.

"But the confirmed case reported by Taiwan is different from what we actually know. The island authorities should give an explanation," it said.

The pressing matter now is to arrange return trips of Taiwan residents in Hubei, the office said, adding the island authorities' attempt to cover up their real purpose of delaying the return of Taiwan compatriots is clear.

Two flights arranged by the mainland that were to take about 890 Taiwan residents from Hubei to the island on Wednesday and Thursday weren't carried out as scheduled, because of obstruction from island authorities.