The father of missing airman Corrie McKeague says he believes more than one person covered up the reason his son disappeared.

Corrie McKeague, 23, has been missing since September last year after he went out with friends in Bury St Edmunds.

Police yesterday arrested a 26-year-old man on suspicion of attempting to pervert the course of justice in relation to the case.

Officers are also preparing to search a rubbish tip which Mr McKeague's mother believes may contain his body.

Corrie McKeague went missing in September A man has been arrested by police investigating his disappearance. His father Martin (right) said he thinks more than one person is involved

Corrie's father, Martin McKeague, said yesterday that he believes a group of people could be hampering the investigation.

He wrote on Facebook: 'In my opinion there's not just one person out there who is perverting the course of justice in the investigation into Corrie's disappearance, but several.'

He also shared a police statement concerning a knife which was found near where Mr McKeague went missing, but which is not thought to be linked to the disappearance.

Mr McKeague quoted the police as saying: 'Police are in possession of this knife after the person it was handed to was spoken to and brought it to the police station.

'The area where the knife was found was searched during the initial stages of the enquiry and no knife was located at that time, it cannot be said when this knife was left in the area or by whom and there is no link between this and Corrie at this time.'

Mr McKeague's mother has also spoke out in regards to the arrest and said the man was not a friend or relative of her son.

Police are now preparing to sift through thousands of tons of rubbish at a dump in Milton near Cambridge.

Investigators made the link to the landfill after a bin lorry made a collection in the area where Mr McKeague was last seen.

Police released CCTV of two people in the area at the time of Mr McKeague's disappearance

Police have released footage of two people they wish to speak to after they were spotted in the area where Mr McKeague was last seen.

Detective Superintendent Katie Elliott said: 'We are continuing to make progress on the investigation and we will be starting the landfill site search as soon as the preparatory work is complete.

'We have been carrying out a lot of enquiries behind the scenes and our work continues to find the truth about what happened to Corrie.'

Mr McKeague's mother, Nicola Urquhart, 48, said: 'I've spoken to the my other sons, Makeyan and Darroch, and the rest of the family, and were just trying so hard not to read more into this than their might be.

'It might end up being nothing or might end up being huge so we don't know. There actually isn't anything that I know that the police haven't put out there.

'They obviously contacted us to let us know that they had somebody in custody and they would be interviewing them.'

Mr McKeague and girlfriend April Oliver. His mother has said she thinks his body may be found

Mrs Urquhart has previously said there is a 'good possibility' her son's body will be found at the landfill site.

Speaking last month, she said: 'I think there's a good possibility that that's where he could have ended up, because I try to look at things logically.

'What we know is that he's not left on foot, he's not still in there now, so he's left in a vehicle. That means he could have gone in a bin and then in the bin lorry, or in one of the other vehicles that were there.

Mrs Urquhart added: 'I don't think anyone who has put Corrie there is going to come forward - they would have done it by now.

'But if someone knows how someone is behaving, if they are behaving oddly, we're going to find Corrie if he's in that landfill, so come forward now, so whoever has put him there doesn't get away with saying he's fallen in a bin and it's an accident.

'At least give us some more closure, not just finding Corrie, but also how he got there and what happened to him.'

Detectives have so far spent more than £300,000 in their search to find Mr McKeague, including using Cadaver dogs, trained to sniff out dead bodies.

Mr McKeague was last seen walking through Bury St Edmunds after a night out in September

The investigation is one of the most expensive ever carried out by Suffolk and Norfolk Constabularies.

Mr McKeague's family have also raised more than £50,000 to draft in private investigators to help and have organised three private searches in their desperate hunt for clues.

Since Corrie's disappearance, it has also emerged that his girlfriend April Oliver, 21, is pregnant with his child.

Miss Oliver said Corrie did not know about the baby which is due in late spring or early summer.

Corrie is originally from Fife in Scotland and moved down to Suffolk to live at RAF Honington where he worked as a gunner and team medic in the air force.

Anyone with information about his disappearance is asked to call the incident room at Suffolk Police on 01473 782019.