---
title: "Jarosław Jerzy Mastalerz — Ownership Dossier"
canonical: https://whiteintel.dev/entity/8bcefcd2-0c4d-523a-b90e-56360b21db57
json: https://whiteintel.dev/api/public/dossier/8bcefcd2-0c4d-523a-b90e-56360b21db57
jurisdiction: EE
source: WhiteIntel corporate-ownership graph
---

# Jarosław Jerzy Mastalerz

**Type:** Person  
**Jurisdiction:** EE  
**Canonical dossier:** https://whiteintel.dev/entity/8bcefcd2-0c4d-523a-b90e-56360b21db57  
**Structured JSON / MCP:** https://whiteintel.dev/api/public/dossier/8bcefcd2-0c4d-523a-b90e-56360b21db57  

## Ownership & control

### Holdings / subsidiaries

- **S18Pa OÜ** (Juhatuse liige) — https://whiteintel.dev/entity/9a230f6c-d67f-5289-b7e4-5713e6c66923
- **Amcast OÜ** (beneficial owner) — https://whiteintel.dev/entity/8b1d6aec-6c57-55de-8346-cc6ccd49305a
- **S18Pa OÜ** (beneficial owner) — https://whiteintel.dev/entity/9a230f6c-d67f-5289-b7e4-5713e6c66923

## Provenance

- estonia_ariregister — https://avaandmed.ariregister.rik.ee/

## Get the full, resolved dossier (agent-callable)

The above is the free teaser. The resolved **multi-hop UBO chain**, ownership **%**, full **financial history**, itemised **assets** and the hop-by-hop **exposure path** are the paid depth — callable as tools from your agent:

```bash
npx -y @whiteintel/mcp-server   # then: get_dossier · trace_ownership_path · check_offshore_exposure
```

Or unlock a one-off cited dossier for **Jarosław Jerzy Mastalerz** — https://whiteintel.dev/entity/8bcefcd2-0c4d-523a-b90e-56360b21db57 · pricing https://whiteintel.dev/pricing.

---

_This is the markdown-for-agents view of the WhiteIntel dossier for **Jarosław Jerzy Mastalerz**. Human view: https://whiteintel.dev/entity/8bcefcd2-0c4d-523a-b90e-56360b21db57 · Structured JSON: https://whiteintel.dev/api/public/dossier/8bcefcd2-0c4d-523a-b90e-56360b21db57._

_Risk levels are heuristic investigative leads, not legal determinations of beneficial ownership. Every claim carries a source; an absent edge means "not yet observed in current sources", not "does not exist"._