Qatar said Monday it has filed three lawsuits in London and New York against Saudi and United Arab Emirates (UAE) banks for allegedly plotting to undermine its currency and bonds.

Doha, which has faced an economic and diplomatic boycott by Gulf rivals since June 2017, also filed legal action in London against the Luxemburg-based Banque Havilland.

"A lawsuit was filed against Banque Havilland in London for its role in designing a plan to attack Qatar's currency and its financial markets," a statement said.

"A separate lawsuit was filed in New York against two financial institutions that engaged in financial market manipulation, First Abu Dhabi Bank and Samba Bank," the statement said.

First Abu Dhabi Bank is the largest lender in the UAE while Samba is one of the leading banks in Saudi Arabia.

Both countries, along with Bahrain and Egypt, are involved in the boycott of Qatar, accusing it of backing radical Islamist groups and seeking closer ties with Iran, Saudi Arabia's archrival.

Doha has repeatedly denied the claims and accused its rivals of seeking regime change.

The lawsuits were filed based on an investigation launched by Doha into market manipulation, according to the statement, which said that further legal action may be taken as the probe was continuing.

Qatar has already taken legal action against the four countries before the International Court of Justice, International Civil Aviation Organization and World Trade Organization.

Doha claimed that the boycotting countries' actions "were designed to destabilize Qatar's currency and financial markets in order to undermine confidence in Qatar's economy."