The case was on Flight NZ8231 Rotorua to Wellington on Thursday and was believed to be linked to the Te Awamutu cluster.
Those at the airport between 4pm and 5pm on Wednesday, October 20, and between 6.30am and 7.15am on Thursday, October 21, are asked to self-monitor for symptoms for 14 days. If symptoms develop they should get tested and stay home until a negative test result and 24 hours after symptoms resolve.
The Ministry of Health said the person who flew to Blenheim spent Wednesday night at a residential address in Tokoroa before flying from Rotorua Airport.
Additionally, two locations of interest in Tokoroa were revealed on Sunday evening: The Bakehouse Cafe and KK Bakery & Cafe between 5.15am and 6am on Thursday last week.
"People living in Tokoroa and Nelson, Tasman and Marlborough, in particular, are asked to monitor the Ministry of Health's locations of interest page, which is regularly updated," the Ministry said in a statement.
"We are also asking residents in Marlborough, Nelson and Tasman with symptoms – no matter how mild – to please get tested, even if they are vaccinated."
As of 1pm on Monday, no locations in Tokoroa had been added as a location of interest.
Interviews with the case, who is currently isolating in Blenheim, are ongoing.
A third contact has returned a negative test following the return of negative tests from two earlier contacts yesterday.
Elsewhere, a pop-up testing site has opened in Ōtorohanga after two people in the Waikato town tested positive for the virus yesterday.
The site is at the Ōtorohanga Sports Club Carpark, at the Island Reserve on Orahiri Terrace and will be open until 3pm.
"As reported last night, these two cases are close contacts of a previously confirmed case from Te Awamutu. They are now isolating locally in dedicated accommodation, with public health oversight," the Ministry said.
"Investigations are continuing today to determine their movements."
It comes as it was revealed there were 109 new community cases of Covid-19 reported today. As at 10am, 47 of these cases are linked - including 30 household contacts - and 62 remain unlinked, with investigations continuing to help determine their connection to the outbreak.