One file identifies a woman in the rebel-held diamond-mining area, who it says is sending President Taylor gems on a daily basis.
In an exclusive report from Freetown, the BBC's Mark Doyle says the documents, from Sierra Leone police files, contain details of specific incidents of arms being sold for diamonds.
One file identifies a woman in the rebel-held diamond-mining area, who it says is sending President Taylor gems on a daily basis.
The allegations surfaced after the United Nations Security Council voted for a global embargo on diamond exports from Sierra Leone, to stop gems funding the war there.
President Taylor has consistently denied such claims.
Police files
One of the intelligence reports says that, two weeks ago, Mr Taylor gave the Sierra Leone rebels a large gun, or rocket launcher, described as a 40-barrel gun.
This weapon was said to have been escorted into Sierra Leone by 200 armed Liberian troops.
Another intelligence report said that on 1 June, two truckloads of arms were sent from Liberia for use by the Sierra Leone rebels.
These trucks reportedly contained rocket-propelled grenades and ammunition for AK-47 rifles.
The documents also name a woman in the Sierra Leone diamond-mining area as President Taylor's representative there.
Our correspondent says the Sierra Leone Government clearly has a political interest in embarrassing Liberia.
But he stresses that the BBC obtained the documents directly from Sierra Leone police files and that the leak did not appear to be part of a co-ordinated political propaganda effort by the Sierra Leone authorities.
UN ban
There has been strong international criticism of Charles Taylor's support for the Sierra Leone rebels.
But until now, very little concrete proof of this support has been forthcoming.
The UN Security Council's worldwide ban on the export of diamonds from Sierra is intended to crack down on the illegal trade through neighbouring countries which has funded the campaign of the Revolutionary United Front rebels (RUF).
The measure will prohibit the export of all diamonds except those whose origin is certified by the government in Freetown.
Hoping to end war
The resolution was proposed by the US, and UK ambassadors at the UN, and includes a tightened arms embargo on the RUF. It will stay in place for an initial period of 18 months.
The RUF rebels, who have a record of brutality and mutilation of civilians during their long-running civil war, currently control the diamond-mining areas of the country.
In May, they took hundreds of UN peacekeepers hostage, and are still holding about 200 in the east of the country.
A Security Council committee, which will police the embargo, will hold a hearing on the link between diamonds and the Sierra Leone conflict.