Officials on May 29 confirmed what we have feared for some time — that a relatively tiny search zone in the southern Indian Ocean is not the final resting place of Malaysia Airlines flight MH370. From an underwater mission covering 850 sq km (320 sq mile) where acoustic “pings” were heard, the area being searched has now been extended to around a 60,000 sq km (23,100 sq mile) zone based on satellite data which remains disputed in some quarters.

The Australia-led search control team estimate it could be August — next year — before this region has been covered, and hopes of finding the Boeing 777’s flight recorders are becoming increasingly dim. With so much uncertainty surrounding the circumstances of MH370’s bizarre disappearance, it has become rich territory for aviation experts, bloggers and conspiracy theorists alike. Here we round up 13 of the most prominent theories as to where the plane ended up, and what went wrong in the first place.

1. Shot down in a military training exercise
2. Flown north and shot down deliberately, prompting cover-up
3. Flown north in the ‘shadow’ of another plane
4. Tried to land on a desert island beach
5. Landed at a US military base
6. Headed for a remote airport in Langkawi, Malaysia
7. A fire throughout the plane
8. An explosion in the cockpit
9. A struggle at altitude
10. A botched hijack attempt
11. Pilot suicide
12. Sabotage – for a life insurance scam or corporate attack
13. A CIA cover-up

Finally, the former prime minister of Malaysia Mahathir Mohamad has waded in with his own theory – suggesting that, one way or another, the CIA is definitely hiding something. In a blog entry posted on 18 May entitled ‘Boeing Technology – What goes up must come down’, Dr Mahathir Mohamad makes ten claims including that the plane was taken over remotely by officials working for Boeing and the CIA.

“The plane is somewhere, maybe without MAS markings,” reads Dr Mohamad’s post on chedet. “Someone is hiding something. It is not fair that MAS and Malaysia should take the blame,” 88-year-old Dr Mahathir, who was Malaysia’s prime minister between 1981 and 2003, alleges. “Airplanes don’t just disappear,” he said, concluding: “For some reason the media will not print anything that involves Boeing or the CIA. I hope my readers will read this.” Boeing have denied Dr Mohamed’s theory.