Mystery surrounds disappearance of French tourist, 18, who was last spotted catching a train outside of Auckland – as family admit the teenager was 'quite disturbed'

• Eloi Jean Rolland, 18, moved to Auckland last September to study English
• He went missing on March 6 in the village of Piha - 45 minutes from the city 
• Mr Rolland's family said he was lonely and 'quite disturbed' before he vanished
• His sister said he was 'determined to return to France as quickly as possible'

The family of a French tourist who mysteriously vanished in New Zealand say the teenager was lonely and 'quite disturbed'.

Eloi Jean Rolland, 18, moved to Auckland last September to study English before he went missing in Piha - 45 minutes east of the city - on March 6.

Mr Rolland's family said he wasn't coping in the months leading up to his disappearance, and suffered 'sentimental setbacks' while in New Zealand. 

'He was determined to return to France as quickly as possible, explaining to everyone that he was homesick,' his sister Aurore Allogho-Boundzanga told the NZ Herald.

Eloi Jean Rolland, 18, moved to Auckland last September to study English before he went missing in Piha - 45 minutes east of the city - on March 6

At 6.30am on the day Mr Rolland went missing, he was captured on CCTV footage boarding a train from Britomart Station in Auckland's CBD

'Personally, I found him quite disturbed in the last months preceding his disappearance.  

'So suicide? An accident ? A bad meeting? A settlement of accounts? Since March 6, the question remains completely in suspense.'

'He assured me that he wanted to see his missing friends again, that he felt too lonely and that he preferred to return as soon as possible to prepare for a test in view of joining the Air Force.'

Ms Allogho-Boundzanga said her brother had been through 'several sentimental disappointments' and 'expressed the desire to return to France as quickly as possible'.

Mr Rolland's family said he was most likely went to the seaside village to collect the area's famed black sand to take home.

The French teen was staying with a host family an hour away in Birkenhead, but failed to return home.

At 6.30am on the day Mr Rolland went missing, he was captured on CCTV footage boarding a train from Britomart Station in Auckland's CBD.

Nearly an hour late he got off the train at Fruitvale Station at New Lynn.

Police believe he may have then walked around 10km to Piha Road, where his phone pinged, at 9.18am.

Mr Rolland hasn't been spotted since and his phone stopped transmitting shortly after.

Police are forensically testing a t shirt that was found 7km south of Piha to determine if it belongs to Mr Rolland.

Detective Senior Sergeant Callum McNeill said police aren't ruling out anything when it comes to how Mr Rolland disappeared. 

The 18-year-old's sister said he was lonely and 'quite disturbed' in the months leading up to his disappearance