Two South African companies have been blacklisted by the United States for allegedly involving in billions of dollars of operations on behalf of the leadership of Iran, a newspaper report said on Sunday.

The two entities, One Vision Investments 5 (Pty) Ltd (OVI) and One Class Properties (Pty) Ltd (OCP), are linked to a property portfolio worth billions of rands, which includes several landmark developments in Cape Town, the Weakend Argus said.

They were named in the U. S. Treasury announcement last week as part of a tangled network of 37 companies operating around the globe, but ultimately traced back to an Iranian controlling entity colorfully named the Execution of Imam Khomeini's Order (EIKO), said the report.

The blacklisting means that the companies are forbidden from doing business in or with the U. S..

The property involved is project-managed by the South African Siltrust Group of companies, but majority-owned by OVI and OCP, as well as a third Iranian-owned entity, which was not listed by the U. S. Treasury, according to the report.

Siltrust's Mustour Abrahams told the paper that the relationship between Siltrust and the Iranian investors dated back to the late 2000s, when he was introduced to Iranian national Gholam Hossein Amouhadi in connection with the development of two properties owned by Amouhadi in Langebaan, South Africa.

The blacklisting of the two entities comes against the backdrop of dangerously escalating tensions between a U. S.-led alliance and Iran, over the latter's refusal to abandon or allow scrutiny of its ongoing nuclear program.